Blood oxygenators are well known in the art and are used in various surgical procedures for introducing oxygen into the blood. For example, during open heart surgery the patient is interconnected with an oxygenator which is disposed outside of the body of a patient, the oxygenator, which is sometimes referred to as a heart-lung machine, will cause oxygen to be introduced into the blood system. Differing forms of oxygenators are known, and one form is referred to as a membrane type wherein the blood is caused to flow to one side of a gas permeable membrane, the other side of the membrane being supplied with oxygen. Where there is sufficient pressure gradient drop between the oxygen supply and the blood, as for example four pounds per square inch, the oxygen will pass through the membrane and into the blood.
While these devices are useful for major surgical procedures, such as open heart surgery, they require close monitoring by attending personnel, are very expensive, and further require that the patient's normal circulatory system be shunted to an oxygenator disposed outside of the body. The time that such a machine can be used with a particular patient is also somewhat limited.
There are many situations where patients require oxygenation of the blood but where it is desirable that a less complex device be provided for such purposes. For example, such a device would be desirable when treating patients with cardiogenic shock, with severe pulmonary insufficiency, with hyaline membrane disease, during severe asthmatic attacks, and also post-operatively where there is a sudden pulmonary insufficiency. It is also desirable that a patient be treated with an oxygenator over a period of time which may be longer than is generally practical with conventional oxygenators.